The invention relates to an illuminating spotlight.
DE 203 12 391 U1 discloses a spotlight having a spot-light housing in which a lamp and a reflector and, on the front beam exit opening, a housing frame for holding auxiliary parts such as front lenses, protective glass screens, gratings or the like are arranged.
The arrangement and fastening of these spotlight devices in and on the spotlight housing requires high precision and thus a large outlay on production, particularly with reference to the devices that influence beams, such as reflectors and lenses, since these devices must be arranged centrally in relation to the optical axis of the spotlight.
A further problem consists in that the spotlight devices connected to the spotlight housing are exposed to substantial mechanical and thermal loads from shocks and, particularly in the case of high power spotlights, to a large dissipation of heat by the spotlight lamp. This applies to a large degree to a protective screen made from glass or plastic that is provided on the beam exit side of the spotlight as shock-hazard protection and explosion protection, there also being provided for the purpose of better thermal insulation two protective screens that are axially spaced apart from one another and enclose between them an air space for heat insulation. In this case, it turns out to be problematical, in turn, to ensure the mutual spacing of the protective screens even in the case of high thermal loading and taking account of violent movements of the illuminating spotlight and of shocks exerted on the illuminating spotlight.
An illuminating spotlight having two protective glass screens arranged at the front is disclosed by DE 87 06 820 U, an air space in the form of a gap being provided between a front glass screen and a second protective glass screen made from armored glass, for the purpose of heat insulation and pressure isolation.
For the purposes of simplifying the design, secure fastening of a cover plate and of more easily changing the lamp of a luminaire, DE 43 13 073 C2 discloses a number of springs, bent in a U-shape, for fastening a cover plate on a cambered reflector inside which the lamp is detachably fastened as luminous means, and whose beam exit opening is covered by a cover plate that transmits the beams and is made from glass, plastic or a grating. The outer edge of the reflector has a number of cutouts or openings in which there are fastened springs that engage the front side of the cover plate from behind with the aid of a projection. The free limbs of the spring bent in a U-shape are in this case plugged through the opening in the reflector edge toward the front side of the luminaire and are locked in such that they are self-supporting.
DE 197 57 055 A1 discloses a luminaire having a cylindrical housing, a reflector and a glass holder which is arranged on the front of the housing and has at least one circular glass disk. The glass holder comprises two glass holding springs that are fastened diametrically on the end face of the housing, and have a spring element, formed from spring sheet metal, with an arcuately curved front side, and limbs that adjoin the front side in a U-shaped fashion and whose ends are formed into fastening eyes. The arcuately curved front side of the glass holding springs has in a circumferential direction of the housing longitudinal slots that delimit resilient strips that, in order to form a glass disk mount, are arcuately curved in alternating sequence outward toward the outside of the spring element and inward toward the rear side of the spring element such that the glass disk can be inserted radially into the depressions thereby formed in the glass holding springs. Arranged in addition on the circumference of the housing as protection against glare is a sliding ring that is sprung with respect to the housing of the luminaire and can be displaced via the glass holding springs.
The spring elements are arranged in a distributed fashion on the circumference of the spotlight device, designed resiliently in a radial direction of the spotlight housing, and connected to the spotlight housing via fastening lugs and/or fastening arms. Two spring arms bearing against the lateral edge of the spotlight device are also angled away with the resilient strips.
U.S. Pat. No. 5,091,835 discloses an illuminating spotlight having a cylindrical spotlight housing and having spotlight devices, connected to the spotlight housing, in the form of a reflector, as well as of a front lens and a protective grid. The connection of the spotlight devices to the spotlight housing is performed via spring elements that are designed as V-shaped control spring clips and either bear against the inside of the spotlight housing, or are plugged onto the front edge of the spotlight housing. The spotlight devices are inserted via depressions in the V-shaped control springs, which are designed to be resilient in a radial direction by means of their shape, and form a fastening lug that is connected to the spotlight housing and from which attached spring arms are angled away at the lateral edge of the spotlight device.
U.S. Pat. No. 6,101,771 discloses a fastening for a cover plate that is arranged at the light emission opening of a cylindrical housing of an illuminating device. The fastening device comprises a number of fastening elements that are arranged in a fashion distributed on the circumference of the housing opening, are connected to a housing flange formed at the housing opening, and have a base with a bore through which it is possible to plug a fastening element that connects an outer fastening ring to the housing flange. The fastening elements have two spring arms coming out of the base, whose ends are angled away to form spring stops, and bear with the latter against the cover plate inserted into the gap between the housing flange and the fastening ring, and exert a contact force on the cover plate.
The spring stops of the fastening elements are designed to be resilient in an axial direction, and exert an axial pressing force on the cover plate, but effect no spring elasticity in an axial direction, only serving exclusively to secure the cover plate in the opening gap between the housing flange and the fastening ring.